If it takes X amount of time to seek and read/write a sector, this timing is critical. This would need to be taken into account for interrupt service timing. This is a major administrative part of NASA.Timing issues8" floppy drives operate with different timing than other drives. ![]() Reliability and operational parameters are well established. This would fall under more scrutiny than most other changes, since it affects the overall operation of the entire system.4) Reliability and environmental specs on the drive are differentthe 8" drives are well known. Requires changes, testing, code review, more testing, qualification, and certification. ![]() 1) Software is on 8" disks moving to a different drive would require all software to be transitioned over to the new medium.2) Drive interface electically specific to the 8" drivethe interface would need to be changed, tested, qualified, and certified.3) Drive translation is specific to 8" diskslow level drivers would need to be changed for the new CHS -> filesystem translation. Quote: I'm not whining over the super processor, just why they can't use a goddamn modern floppy drive insted of a USED 8"er from frikkin' ebay, for crying out loud. Same thing goes for the Shuttle.Sure we *SHOULD* be able to substitute a 3.5" floppy for an 8", but will everything else work out right? It might, but it's overall cheaper to just replace with like gear than certify use of other gear, especially considering the Service life of the shuttle. Lots of time of money would have to spent ( Lots means > several million ) to certify the new "hot" 's not so much the INS systems themselves, but also the software that goes into developing the code that runs on the systems, the compilers, the development stations themselves, etc. ) and they need replacement parts-exact replacement parts. Why? the service life of commercial aircraft is upwards of 30 years, ( Just how old IS that DC9 you were in last week. vendors of "classic" equipment laughed when I called and told them what I needed), as well as maintaining old HP gear from the early 80s. My last two adventures were trying to get a Sun 3/260 fixed/reloaded (we settled on using a 3/60 pizzabox instead, parts obtained on ebay. Faster processors may do the job better and more efficiently, but if their timing screws up the timing/clock bus, the whole system can be Fsck'd and then what do you do hurtling around at 17,000+ mph ? I'm temping back at an old place of employment where they make Inertial Navigation systems and GPS systems for commercial and high end biz jets. It's not so much the equipment is old.the SYSTEM itself is old, and as a whole may depend on the older gear. They are just trying to hold out till 2012 or whatever when the shuttle's predecessor is launched. Hence they just need to buy more of the stuff they are comfortable with. ![]() Its called they aren't going to change the design because there is no need at this point, and it would be too costly. It would be similar to using a p4 2000 today. to me, that statement is crazy, because how was that harware "proven" in 1981. Even a BX system would be considered too much of a risk, and we all know how stable they're considered by computer people. This kind of old hardware isn't going into ground control computers or anything, it's for the dedicated onboard systems that absolutely must not fail. That's why a year ago the Hubble was "upgraded" to a 486. It takes a long time to get hardware absolutely 100% perfect, which is what NASA demands. Quote:Originally posted by Primeous: Stability. View image: /infopop/emoticons/icon_cool.gif ![]() 4 micron transistor is less susceptible to radiation damage than a. View image: /infopop/emoticons/icon_mad.gif quote:Another big factor is the size of the structures on the chip. 100% perfect?!?Then why, oh why, are theyquote: Nasa is hunting internet sale and auction sites like Yahoo and e-Bay for shuttle parts Shee-yeah?!!! Like that crap will be "perfect"?This pisses me off. Oh, come on!10 years!! We are talking about floppy drives here! View image: /infopop/emoticons/icon_eek.gif quote: The shuttle operators also need eight-inch floppy disk drives that went out of fashion nearly 20 years ago, and have long since been replaced by much smaller disk drives and CD-ROMs.
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